The separation of signal jitter into various components, such as Random Jitter (Rj) and Deterministic Jitter (Dj) helps to identify possible causes of errors in the signals and allows estimation of system error rates. This is quite useful in the analysis of edge jitter in serial data communications signals and in signals from computer busses. This jitter separation is referred to as RjDj separation, can be accomplished by a number of techniques, including those based on spectral analysis.
For RjDj separation techniques that rely on spectral analysis, a key problem is that of identifying spectral impulses that signify narrowband deterministic signals, as distinguished from gaussian noise. The reliability and repeatability of-this identification process has a direct bearing on the accuracy of the RjDj estimates.
The identification of narrowband deterministic signals that are masked by additive noise is a signal-processing problem that has been investigated at length. Radar target detection and estimation require consideration of this problem as is known from, Detection of Signals in Noise by Anthony D. Whalen, Academic Press, New York, 1971. It is also known that some medical diagnostic techniques require consideration of this problem.
International Patent Application Publication WO 99/39216, entitled Method and Apparatus for Jitter Analysis, to WaveCrest Corporation, teaches a particular method (to be described below) in the specific field of RjDj separation.